https://oak.chosun.ac.kr/handle/2020.oak/19129 2026-04-09T17:44:05Z https://oak.chosun.ac.kr/handle/2020.oak/19194 Title: 국내외 무연탄 활용을 위한 석탄성형 기술개발 Author(s): 김양수; 한오형; 박철현; 최홍일 Abstract: Coal briquetting for utilization of domestic and overseas anthracite has been studied. In preliminary test to determine the optimal briquetting conditions using a lab-scale briquetting rig unit designed and assembled, briquetting rate and strength of pellet increased as content of domestic anthracite increased, however caloric value (kcal/kg) decreased. The optimal mixture ratio of pellet was accomplished at the condition of Jang-sung coal : Vietnam coal : moisture = 60% : 30% : 10%. From coal briquetting testwork based on the pellet mixture ratio, B-6 briquette (Jang-sung/Vietnam coal) achieved combustion time of over 330min with caloric value of more than 4,300kcal/kg satisfying KS briquette standard. Especially the B-6 was superior in terms of reduction of harmful gas such as CO, NOX and SO2. 2015-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19198 Title: LED 광원을 이용한 피부미용기기의 방열설계에 대한 수치적 연구 Author(s): 함정균; 신윤찬; 조홍현 Abstract: Nowadays, the portable skin care devices are widely used due to the convenience, low cost, and short using time. Therefore, a lot of study on the development of skin care devices have been conducted. In this study, the heat generation and distribution of skin care devide using LED light is investigated and the effect of temperature on the skin is predicted by using CFD analysis. As a result, the heat generation of LED increases as the power consumption of the portable LED skin care device increases. When the power consumption is 4.223 W, average LED temperature of model 1 increases by 42.1°C, while it decreases by 1.7°C for model 2 and model 3 compared to that of model 1. Average temperature of LED and FPCB for model 2 is lower than that for model 3. Moreover, it is distributed on the surface uniformly because the some vents for heat rejection are located at the center of mask where heat is concentrated. 2015-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19197 Title: 직렬 RLC 공진을 이용한 저전력 LED 구동회로 Author(s): 박성호; 김충원 Abstract: In this paper, a simple and robust low-power LED driver using a series RLC resonant circuit is proposed and discussed. The characteristic of the series RLC resonant circuit is that the voltages across the capacitor and the inductor are Q factor times the input voltage. Thus, it will be possible to drive the LED arrays in the series RLC resonant circuit which having a sufficient Q. MATLAB simulations and the experimental results showed that the proposed LED driver is very efficient and robust for driving LEDs with a very low input voltage less than 1.5 Vrms. 2015-12-31T15:00:00Z https://oak.chosun.ac.kr/handle/2020.oak/19193 Title: 열전소자의 신뢰성평가를 위한 비접촉 공중 초음파 탐상기법의 적용 Author(s): 고가진; 김재열; 이경일; 김원배 Abstract: The Thermoelectric Module is a new type of artificial refrigeration technology development on the basis of the discovery in 1834 of Peltier effect. The use of Thermoelectric Module is used as a heat pump has the advantages of no pollution, small size, no noise and other characteristics in line with environmental protection requirements, low power consumption has been widely used in many industries. Thermoelectric Module production from material to product assembly process has certain reference now, but with the application of Thermoelectric Module is more and more widely than before, people's requirement on the efficiency of Thermoelectric Module and reliability becomes higher. people pay more deep research on the Thermoelectric Module. At present, the research for efficiency of Thermoelectric Module on the international is mainly concentrated in the material. However, the research of materials has certain limit, the research of materials had reached a bottleneck. NAUT (Non-contact Air coupled Ultrasonic Testing) is an inspection technique to remedy the existing contact inspection by supplementing energy loss created by differences of acoustic impedance between the solid and the air with high power ultrasonic Pulser Receiver, PRE-AMP, and high sensitivity probe, and enabling the ultrasonic inspection which uses the air as a medium. As explained above, in this thesis will show you how to use the NAUT to check out the defects inside. According to the scanning picture to judge the position and the size of defects inside. Above all, solved the problem of the detection of joint situation, and this method could give some help to improve the performance of Thermoelectric Module. 2015-12-31T15:00:00Z